Thread: Post spacing for handrails

I'm looking in my Allan Staines book and it appears only to be limited by the size of teh hand rail that you use. There is a span table for handrails on edge or on flat. 3.0m looks possible but you would need a decent size rail.

If you put a handrail it probably should meet the standards. At a minimum it gives you guide as to how to construct it so that it doesn't feel to weak.

There is a bit of detail on the handrails ... PM me if you don't have access to the Allan Staines books.

I believe aesthetics may play the biggest part in your decision here.
To span 3m you will need a fairly large section timber to avoid having it sag or flex under weight. Image the weight of a few mates leaning on it or perhaps even sitting on it...
90 x 45 @3m would flex with the weight of just one person leaning on it. (And this would flex in both directions.)
90 x 90 @3m would be much better however you're then looking at a chunky and expensive piece of timber.

If you were to be using some intermediate timber supports as the balustrade then this would assist however I believe you are wanting to use stainless steel wire?

To stay within the regulations for s/steel balustrade for decks > 1m off the ground, as you say the BCA tables only go up to 2.5m. You'll also find that for 3mm wire they'll have to be spaced at 60mm or 80mm if using 4mm wire. For a handrail approx 1.1m high you're then looking at up to 18 runs of wire! Price it up first as you may find it expensive! Also 12m long is probably too long to do with one length of wire - you won't be able to get sufficient tension to minimise the deflection. This will probably need to be split into 2 x 6m or maybe smaller.

Given that you are not >1m above the ground I would go for something that looks good and provides a satisfactory level of safety. There is something in the regulations somewhere about the spacing of balustrade to prevent a child from getting their head stuck. From memory it is 125mm??? Perhaps base your design around this.

One other point about attaching the handrail posts is well illustrated in Allan Staines book. Extend the bottom of the post down past the bearer and then attach a bracing piece of timber to the bottom of the post and back inwards along the joist - forming a triangle brace. This will add a lot of rigidity to the post. Let me know if you don't have the book and I'll sketch something up to explain further.

Good luck!

Thanks Loki. Great info.
I think I'll go with 2.4m spacing. That would give me exactly 6 posts for the 12m span, and I'll be within guidelines....

The bracing is not needed as the post is going all the way into the ground and being cemented in. A bit of overkill I know, but I want that extra support, plus I have some spare posts in the garage that I'd like to put to good use.

If I go for the 2.4m span, could you advise what size of timber I'd need for the top of the handrail...would 90x45 suit with no flex?

Ps. Hows ur deck looking loki?

Cheers

I have stainless wire and the posts are spaced at about 2.0 - 2.1 m. These are probably too far apart, and could have had a small intermediate post to help stop the wire deflection. Longest run is 6.5 metres. Due to design of the deck

there is a requiremsnt of no more than 100 mm between rails, and is tested by passing a 100mm ball through, or so I was told. The inspector turned up, I told him they were 90 mm apart and he gave a few a wriggle and was happy with it.

oohsam,
I go for looks too, and I have never done a wire balustrade without some sort of support at max. 1500 centers. This stops the wires sagging if a kid tries to climb up. If you have the wire vertical it stops the rails bending inwards to a certain extent.

Of course this is not to say that these are the main support.
I always work in steel, so I could have my main column supports at 3500 and have two small ones in between.
A bit like droppers on a wire fence, but fixed at floor and rail.

For these I've use lightweight RHS box sections, flat and even SS flat pre-drilled for the wires.

BCA says that your max. spacing is 125. That is you can't get a 125 diameter ball through the balustrade at any point.

I have always used an industrial supplier for my SS fittings and wire, Bullivants comes to mind but there are others. Marine places are poisonous with their prices.

Best of luck with it.
Cheers
Bill

Hmm.
ok...Some good info there.
We dont have kids but may have one day, and we will have some kids over at some stage in our lives, which is the main reason why I want the baulstrade.

I was going to do them at 120mm to be within regulation, but now im a little worried at having them spanned 2.4m.

Is it not possible to just retension them when they come a little saggy?
I like the idea of having a support at 1500 but i dont like how they would look. I will probably be going through miami steel for the bualstrade, their prices seem pretty good.

Here's a suggestion:

Posts at 2.4m, handrail 90 x 45 (laid flat so you have a nice surface to rest your beer on) with an intermediate support at 1.2m. This could be a flat piece of s/steel with holes for the wire to pass through.

You won't be blocking out your view with too many posts or too large a handrail yet will still have sufficient support for the wire.

I've got max 1.8m between supports for my handrail (90 x 41) but would be hesitant to stretch that to 2.4m.

Loki

ps My deck's coming along - slowly! I'll take some pics when I get home and update tonight.

Ok, that sounds good. I'll put the posts in tonight.

What do you reccomend for the flat piece of SS for intermediate supports?

Just called Keble steel. They said I would definatly need a SS dropper at 1.2m centres for support as 2.4m is too much to span. They are $50 each.
The adjuster things are $7.10 each and the Fork Terminal is $3.18 each.
Wire is $1.34 a meter.
Saddles are 50c

They reccomend doing 100mm runs, 9 of them.

That would cost me about $25 per run including calbe...thats $225 for the length of the deck and $126 for the width of the deck. Which is within my budget.

He said one run of cable is plenty. no need to mid tension or anything. I could also put a tensioner on the other end for extra tension but not required.

Miami steel has teh following chart re the new regs for wire
http://steel-fittings.com/regulations.htm.

100 mm is the max spacing for wires allowed for decks above 1 metre according to their chart.

I just rechecked and my council require 125mm when i did it about 4 years ago as teh new requirments for wire didn't exist. I had 110mm, not 90 as I posted earlier. Check with yours, although you are under 1m it doesn;t apply

If above 1 metre wire must now conform to the following table to prevent a 125mm ball being forced through the wires. (same table as miami steel, but has a better overal explanation)
http://www.nillumbik.vic.gov.au/File...&Handrails.pdf

Ok got the 4 posts in....
I re-measured and they total length was 1170mm, so I spaced them 234mm. Everything went pretty perfect. Didnt take long to do. Dug the holes about 300mm deep for cement (not yet cemented in). 2 bolts into bearers per post, then I braced the posts so they dont warp and twist until I cut them to length and put the top handrail peice on.

I will cement them in tomorrow after work, and sand them down and plane the corners off to make them neat. Then I'll cut them to length on saturday and hopefully I'll have the balustrade by then so I can thread the steel cables through!

Here is a pic for your troubles!